Preparation of novel homo- and copolymers using atom transfer radical polymerization

Abstract

The present invention is directed to a process of atom (or group) transfer radical polymerization for the synthesis of novel homopolymer or a block or graft copolymer, optionally containing at least one polar group, with well defined molecular architecture and narrow polydispersity index, in the presence of an initiating system comprising (i) an initiator having a radically transferrable atom or group, (ii) a transition metal compound, and (iii) a ligand; the present invention is also directed to the synthesis of a macromolecule having at least two halogen groups which can be used as a macroinitiator component (i) to subsequently form a block or graft copolymer by an atom or group transfer radical polymerization process; the present invention is also directed to a process of atom or group transfer radical polymerization for the synthesis of a branched or hyperbranched polymer; in addition, the present invention is directed to a process of atom or group transfer radical polymerization for the synthesis of a macroinitiator which can subsequently be used to produce a block or graft copolymer.

Claims

1. A process for making a (co)polymer, comprising the steps of:

(a) polymerizing an AB.sub.2 monomer of formula (V): ##STR9## in the presence of a catalyst system, comprising: (i) a transition metal compound and

(ii) a ligand able to coordinate with said transition metal compound

to thereby initiate polymerization of said monomer and form a branched polymer;

wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of H, halogen, CF.sub.3, straight or branched C.sub.1 -C.sub.20 alkyl,.alpha.,.beta.-unsaturated straight or branched C.sub.2 -C.sub.10 alkenyl or alkynyl,.alpha.,.beta.-unsaturated straight or branched C.sub.2 -C.sub.6 alkenyl substituted with a halogen, C.sub.3 -C.sub.8 cycloalkyl, hetercyclyl, C(.dbd.Y)R.sup.5, C(.dbd.Y)NR.sup.6 R.sup.7 and YC(.dbd.Y)R.sup.8, where Y may be NR.sup.8 or O, R.sup.5 is C.sub.2 -C.sub.20 -alkyl, C.sub.2 -C.sub.20 alkoxy, aryloxy or heterocyclyloxy, R.sup.6 and R.sup.7 are independently H or alkyl of from 1 to 20 carbon atoms, or R.sup.6 and R.sup.7 may be joined together to form a C.sub.2 -C.sub.5 alkylene group, thus forming a 3- to 6-membered ring, and R.sup.8 is H, straight or branched C.sub.1 -C.sub.20 alkyl or aryl; and

R.sup.3 is selected from the group consisting of H, halogen, C.sub.1 -C.sub.6 alkyl, COOR.sup.9, where R.sup.9 is H, an alkali metal, or a C.sub.1 -C.sub.6 alkyl group, or aryl; and

R.sub.2.sup.4 is an organic spacer group and A is selected from the group consisting of R.sub.2.sup.4 '--X and X, where X is a halogen, and R.sub.2.sup.4 ' is selected from the group consisting of straight or branched C.sub.2 -C.sub.20 alkyl,.alpha.,.beta.-unsaturated straight or branched C.sub.2 -C.sub.10 alkenyl or alkynyl,.alpha.,.beta.-unsaturated straight or branched C.sub.2 -C.sub.6 -alkenyl, C.sub.3 -C.sub.8 cycloalkyl, heterocyclyl, C(.dbd.Y)R.sup.5, C(.dbd.Y)NR.sup.6 R.sup.7 and YC(.dbd.Y)R.sup.8, C(.dbd.Y)--Y--R.sup.5 --C(.dbd.Y)--R.sup.8 where Y may be NR.sup.8 or O, R.sup.5 is alkyl of from 1 to 20 carbon atoms, alkoxy of from 1 to 20 carbon atoms, aryloxy or heterocyclyloxy, R.sup.6 and R.sup.7 are independently H or alkyl of from 1 to 20 carbon atoms, or R.sup.6 and R.sup.7 may be joined together to form an alkylene group of from 2 to 5 carbon atoms, thus forming a 3- to 6-membered ring, and R.sup.8 is H, straight or branched C.sub.1 -C.sub.20 alkyl and aryl; and

R.sup.1 and R.sup.3 may be joined to form a group of the formula (CH.sub.2).sub.n' or C(.dbd.O)--Y--C(.dbd.O), where n' is from 2 to 6 and Y is as defined above.

2. The process of claim 1, wherein said AB.sub.2 monomer is selected from the group consisting of p-chloromethylstyrene, methyl-a-chloroacrylate 2-(2-bromopropionoxy) ethyl acrylate, p-chlorosulfonyl styrene, vinyl chloroacetate and chloroacrylonitrile.

3. The process of claim 1, wherein said branched polymer is a hyperbranched polymer having one or more radically transferable atoms or groups and wherein said process further comprises:

(b) polymerizing a vinyl monomer in the presence of a catalyst system comprising:

(i) said hyperbranched polymer having one or more radically transferable atoms or groups,

(ii) a transition metal compound, and

(iii) a ligand, able to coordinate with said transition metal compound and initiate polymerization of said vinyl monomer.

4. The process of claim 3, wherein said hyperbranched polymer having one or more radically transferable atoms or groups is a multi-functional initiator and wherein the copolymer formed is a multi-armed star copolymer.

5. The process of claim 4, wherein said AB2 monomer is chloromethyl styrene, and said vinyl monomer is butyl acrylate.

6. A multi-armed star copolymer prepared by the process as claimed in claim 5.

7. The process of claim 3, wherein said AB2 monomer is 2-(2-bromopropionoxy) ethyl acrylate and said vinyl monomer is butyl acrylate.

8. A multi-armed star copolymer prepared by the process as claimed in claim 7.